1. Field of the Invention
This invention pertains to gas fired furnaces and more particularly to direct-fired make-up air furnaces.
2. Background Information
Conventional direct-fired make-up air furnaces have a significantly large cabinet which accommodates a blower, a burner, various ducts, and air flow control elements. One of the reasons why such cabinets are made so large is the necessity of installation of large dampers regulating the volume of air flow entering the cabinet. Dampers require the space for a frame support structure, an air duct or plenum connected to the damper and the remaining ductwork, and a valve operating mechanism. Also, additional space is needed in order to separate the motor of an air blower from the radiant heat emanating from a gas burner.
If the motor is located too close to the burner, the motor will become overheated in a short period of time. Therefore, it has been a common practice to locate the motor outside the burner compartment in order to prevent the motor overheating.
A furnace constructed in accordance with the subject invention reduces the size of a conventional furnace cabinet by approximately 20%, thereby saving the space which may be critical under certain circumstances and costs associated with unnecessary sheet metal. The new furnace provides a more streamlined and aesthetically appealing structure without sacrifice of furnace efficiency.
A more detailed description of the novel furnace is set forth hereinbelow.